Sipuleucel-T (Provenge) has shown in clinical trials that it prolongs overall survival (OS) in asymptomatic or minimally symptomatic men with castrate resistant prostate cancer (CRPC). Unlike many other treatments for men with CRPC there are not any reliable biomarkers to show that it is working for any individual. There is also a lack of markers that can be used for predictors. This has led many men to become cynical about Provenge’s value.
A small study was conducted which prospectively evaluated biomarkers in men receiving Provenge to identify predictors of efficacy and OS.
The researchers evaluated as potential markers circulating tumor cells (CTC), PSA, prostatic acid phosphatase (PAP), albumin (Alb), hemoglobin (Hb), serum alkaline phosphatase (SAP), LDH, C-reactive protein (CRP) and ?2-microglobulin (?2m). They looked at 92 men who received Provenge with a median age of 69 (48-90). The median follow-up was 14 (1.3 –34.7) months.
They found that there was a correlation of improved OS in men with lower PSA values, higher Hb, and albumin. These three parameters support the hypothesis that Provenge is more effective with low disease burden. They also found that there was a possible prediction of early disease progression by higher levels of ?2m and LDH. This warrants further study.
TAKE HOME – Start Provenge sooner than later. The very best time is immediately after becoming castrate resistant.
J Clin Oncol 32, 2014 (suppl 4; abstr 134); Mehmet Faith Hepgur, Tanya B. Dorff, Lucy Brining, Jie Cai, Jacek K. Pinski, Mary Reed, Michael Luther, Betty Chan, David I. Quinn
Joel T. Nowak, M.A., M.S.W.